ENZYMES: Phosphoglucomutase PGM: (a) Confirm the presence of tyrosine at the active site in PGM from other tissues and organisms. (b) Investigate the presence of arginine at the active site. In both instances use specific tyrosine and arginine modifying reagents. (c) Further studies on adenylcyclase, leukokininase, tuftsin-endocarboxypeptidase and tuftsin degrading enzymes. TUFTSIN, the phagocyte activating tetrapeptide Thr-Lys-Pro-Arg. Investigate, in depth the stimulation of various activities of the macrophage and granulocyte which have been demonstrated already as follows: (a) Tumoricidal activity, to be extended to various syngeneic macrophages and target cells in vitro and in vivo. (b) Bactericidal activity, to be extended to various pathogenic organisms. (c) Dissect the various biochemical steps in the stimulation of the immunogenic function of the macrophage and possibly the granulocyte. (d) Isolate the reversibly saturable receptors and the covalently bonded receptors from neutrophils and macrophages. (e) Investigate the mechanism of stimulation of random motility and phagocytosis with reference to contractile proteins of the phagocytes. (f) Investigate the biochemical steps in the stimulation of hexose monophosphate shunt. Further studies on cell recognition among blood leukocytes.